Of the genus Corvus were procured three species, two of which are apparently not described. The first is a very beautiful jay, the head and belly black; back, wings, and tail of a beautiful blue; the bill of the male is yellow, and of the female black; the legs yellow. It was first seen and shot near Sisal, on the way up to Merida, and afterward several other specimens were obtained in different parts of the country, for they are numerous throughout Yucatan. The other was first met with at Uxmal, where a female was shot, and afterward two males. They are of a dark brown on the head, neck, back, and tail; belly white; bill of male black, and female yellow; they have a most singular formation of the trachea, there being a sort of membranous sack or bag coming off in front of the trachea at about the middle of its length, and intimately connected with the skin of the neck; this formation, together with the great muscularity of the larynx, may account for their excessively loud and disagreeable cry. The other jay is the Corvus Peruvianus, Peruvian jay. (Shaw, vol. viii., plate 27.) This most beautiful bird is found in great abundance in almost all parts of Yucatan, which is probably its native country, as it is mentioned as rare in Peru. Of the genus Psittacus were procured four species, three of which have been described, and perhaps the fourth also; but, as the specimen is bad, it is not easy to ascertain positively whether it has or not. One, the Psittacus Albifrons (Ind. Orn., vol. i., p. 119), white-crowned parrot (Shaw vol. viii., p. 519), is very numerous throughout Yucatan. It is a beautiful bird, coloured with green, blue, red, white, and yellow. Another, supposed to be the Psittacus Guianensis (Gen. Lil., vol. i., p. 323), the green parrot of Guiana (Gen. Syn., i., 231), is not so abundant as the last, but still quite numerous. The specimens were procured at Ticul, and some were afterward shot near Iturbide. The third species was not seen in the wild state, the only specimen procured being given to Dr. Cabot, alive, by the padre Curillo, of Ticul. It is the Psittacus Macao (Ind. Orn., vol. i., p. 82), red and blue macaw (Gen. Syn., i., 199). Of the genus Ramphastos one specimen was procured, the yellow-breasted toucan (Gen. Syn., vol. i., p. 326), Ramphastos Tucanus (Ind. Orn., vol. i., p. 136). This specimen does not agree with the description in Latham, but is the same as the one described by Mr. Edwards from a living specimen in Lord Spencer's collection. It was procured at Uxmal on the day when Dr. Cabot went down to the hacienda to operate on an Indian's leg. Two or three different species were afterward seen at Macoba, but Dr. C. did not succeed in killing any of them.